A. Field of the Invention
The present invention relates to devices and methods for monitoring biopotentials. More particularly, but without limitation, the present invention relates to a method and device for monitoring or sensing a biopotential and wirelessly transmitting the monitored condition within a predetermined distance.
B. Problems in the Art
Biopotential sensors are known in the art. In a conventional arrangement, such as with electrocardiograph (ECG) leads, the sensors/leads are connected to a monitor or display through wires. The use of wire connections can create problems.
For example, there are times when a patient to whom ECG leads are attached will need to be moved very quickly to a remote part of the hospital. In this scenario, the electrodes must either be removed from the patient or the ECG monitor must also be moved with the patient. Removing the electrodes from the patient requires additional time which is undesirable when the patient is facing a situation that must be acted on quickly. If the leads are left on the patient, then the ECG monitor must be moved with the patient, also requiring additional time and/or personnel to aide in moving the monitor. Also, the wires between the leads and the monitor can create further hazards to the patient and the equipment.
In addition to creating problems when a patient is being moved, wire connections can also cause problems when a patient is stationary. For example, hospital personnel can accidentally trip over a wire or the patient could accidentally jerk one of the leads free from the monitor. If the disconnection of the electrode from the monitor is not detected and acted upon, a patient could conceivably suffer needless deleterious consequences. There is a need in the art for a biopotential sensing device and method which minimizes the use of wire connections.
In an attempt to solve some of these problems, wireless ECGs have been invented. However, with an increase in the use of wireless ECGs and other wireless communication devices, the probability of electromagnetic interference increases. In addition, in an attempt to control health care costs, there has been an increase in the number of hospital rooms where more than one patient occupies a given room. This makes the probability of electromagnetic interference even greater. In these situations, it is desirable that there be no cross-linkage, or electromagnetic interference, between monitoring devices of two patients in close physical proximity. None of the known wireless ECGs have attempted to solve the problem of electromagnetic interference between analogous devices, monitoring different patients, through limitation of the power of the output signal.
While the problem of electromagnetic interference is of particular concern in the hospital setting, there are other situations in which interference can be problematic. Given the increase in the number of wireless communication devices that are used within a home (e.g., cell phones, remote controls) there is a need in the art for a method and device which allows for the use of multiple wireless communication devices while also limiting electromagnetic interference. It will be apparent to those skilled in the art that the teachings of this specification can be applied outside of the medical context.
Therefore, it is a primary object of the present invention to provide a wireless biopotential sensing device and method which solves problems and deficiencies in the art.
It is a further object of the present invention to provide a method and device which senses biopotentials and transmits the sensed biopotential using an ultra short range radio frequency.
It is a further object of the present invention to provide a biopotential sensor and transmitter combination which outputs signals that do not interfere with similar devices.
It is a further object of the present invention to minimize multipath interference.
It is a further object of the present invention to provide an output signal which maintains a patient""s privacy.
It is a further object of the present invention to provide a wireless biopotential sensor and transmitter which minimizes battery discharge.
It is a further object of the invention to provide a biopotential sensing system and method which is capable of two-way communications between an electrode and a remote transceiver.
These, as well as objects and features of the present invention, will be apparent from the following detailed description and claims in conjunction with the accompanying drawings.
The present invention includes a new biopotential monitoring system which has the advantages of limiting electromagnetic interference while consuming low power. The biopotential monitoring system includes a biopotential sensor. The biopotential monitoring system also includes a transmitter which is in operative communication with the sensor. The transmitter is adapted to broadcast a first signal which is modulated by a sensed biopotential. The transmitter is further adapted to limit the power of the first signal so that the signal attenuates within a predetermined distance from the transmitter.
The biopotential monitoring system may also include a receiver which is adapted to receive the first signal. Optionally, the receiver may be in operative communication with a computer to store or record the received signal. In one embodiment, the biopotential monitoring system can also include a second receiver which can receive signals to instruct the sensor to perform various functions, such as turning the power off, transmitting a signal, or waiting in standby mode.
The present invention can also include a method of monitoring a biopotential signal. A method of monitoring a biopotential signal includes the steps of sensing a biopotential signal with a biopotential sensor, and broadcasting a first signal which is modulated by the sensed biopotential. The method also includes the step of limiting the power of the first signal so that it attenuates within a predetermined distance from the transmitter. The method can optionally include the steps of receiving the broadcast signal at a first receiver and communicating the broadcast signal to a computer where it can be stored and/or analyzed. Further, the method may include additional steps such as transmitting a second signal to a biopotential sensor to facilitate a secondary function.